The cooperation between hardware and software is very important to me. That's why I came up with the idea to develop the Grape-Express Mini. I wanted to have a board with a sleek design and a lot of power. It should be independent and equipped with the latest technology on the market. The board has to be user-friendly so beginners can easily start a project. So you can also use Arduino IDE to program the Grape-Express Mini.
What is Grape-Express Mini
The Grape Express mini is a powerful ultimate developer and prototyping board. It can be used for any application. On the board is a powerful ATMEGA2560. This can be programmed via JTAG, ISP or via the micro USB with the help of a PC. The simple design makes it possible to complete a project as quickly as possible. In addition to the processor, the Grape-Express Mini offers many more features. So all sorts of I/Os are available from the processor on the headers. With the help of the RN171, a connection can be established with the Internet for example data can be inserted into the Internet into a table and many more cool things that the module offers. There is a external connection for the antenna for a lot more power. On the Board is a RN4871 Bluetooth 4.2 Module (BLE). With this module, smart devices or smartphones can communicate with each other and you can do smart home accessoires. These two modules can be controlled externally as well as with the microcontroller. To display texts, graphics and numbers, there is an integrated 1.3" OLED display. With the connector system it is possible to connect things like sensors or additional modules on both sides. Cables always get in the way, that's why the board has a lithium-ion battery with power up to six hours. This is automatically charged if an external power supply is connected and automatically switches to the battery when it is removed. This process works without interruption in the program. All these features are there for a project or prototype to finish as soon as possible. And these are not all features where the board offers.
Software is very important. The most important, for a microcontroller project, is the software that brings the hardware to life. In order for the Grape-Express Mini to be ready for your project without too much code, software modules are made. With these software modules you can customize your project individually. Adjust parameters and other things to match your project. The software is optimized for the board, so this board is special too. It is also possible to create a project with the Arduino studio.
How can you use it?
The Grape-Express Mini is perfect for developing prototypes or projects. The board has a lot of features that make it easier to develop. So the board is a combination of different main elements and not a board where all basic components have to be put together first. In addition, the board is independent of a power source, so for example, while traveling the board can be programmed without a cabling effort. The project that you create can range from something as simple as a timer to blink an LED to something as complex as a mini computer with a user interface.
This is an example of a small project withe two CO2 sensors to compare, a LED matrix and a simple counter that shows on the small LEDs. This allows data to be evaluated and text to be displayed on the LED matrix.
Project created in 5 minutes
This is a project created in 5 minutes. By simply plugging in additional electronics, a small software can be created within minutes, making the module an element of the Grape-Express Mini. With this example I would like to show you how simple the Grape-Express Mini Board is and how fast you get to a result.
Grape-express Mini offers a selection of communication tools such as WiFi and Bluetooth. These modules have been specially selected as their properties lead to an effective work. Both modules can receive updates from manufacturers. Both can be programmed with ASCII commands and presets. So no big program code has to be written. The modules have standards that do not even exist with certain modules. So these are perfect for working with the microcontroller. For this board, the modules RN171 for WiFi and the RN4871 for Bluetooth were used. The WiFi module has status LEDs with which it indicates in which mode it works and if the modules are connected.
Most important features:
- Configured using Simple ASCII Commands
- 32Bit CPU, 128KB RAM, 2MB ROM
- Supports Infrastructure and SoftAp Networking Modes
- Built-in Networking Applications: TCP, UDP, DHCP, DNS, ICMP, ARP, HTTP Client, and FTP Client
- External Antenna Connection
- Security: WEP-128, WPA-PSK (TKIP), WPA2-PSK (AES)
- Ultra Low-Power Sleep Mode (4 uA)
- And more...
Bluetooth 4.2 (BLE)
Most important features:
- ASCII Command Interface API over UART
- 8051 at 16MHz, 32KB ROM, 24KB SRAM, 256KB flash
- On-Board Bluetooth Low Energy (BLE) Stack
- Beacon Private Service for Beacon Services
- UART Transparent Service for Serial Data Applications
- GAP, GATT, SM, L2CAP and Integrated Public Profiles
- Create up to Five Public and Four Private Services
- And more...
The Grape-Express Mini has a lithium-ion battery. The power management controls the charging and discharging of the battery. It is possible to load the board with a Micro USB, connecting or removing the USB will not cause any power interruption. The battery is charged in 20 minutes and supplies power to the board for up to 6 hours. The power management has status LEDs that indicate the state of charge of the battery as well as the mode in which the power management is working.
The Grape-express mini was developed so that it has several interfaces to program it. JTAG and ISP with the ICE-Programmer from Atmel. The board has also USB so it is possible to program with a PC. With the help of a bootloader that can be loaded into the microcontroller via ISP, you can also load the program via USB from the PC into the board, just like Arduino.
The evaluated USB chip has a high performance and transmits data very fast and reliable. This chip contains the standard rules of the USB and UART interface.
The Grape-Express Mini is compatible to all shields of Arduino use the simple adapter which is included for free:
- Powerful Grape-Express Mini (16MHz)
- Dimensions L = 100mm, B = 49mm, H = 22mm
- 256KB Flash, 4KB EEPROM, 8KB RAM
- WiFi (also withe ASCII) withe external antenna
- Bluetooth 4.2 BLE (Bluetooth Low Energy)
- Bluetooth and WiFi can be externally programmed and updates received
- Multiple programming connectors (USB, ISP, JTAG)
- 1,3" OLED Display
- Internal 32,567kHz crystal
- Safety in transfer data between microcontroller and WiFi, Bluetooth and external programmer.
- WiFi and Bluetooth GPIO protection
- Power switch on/off
- Maximum 1,9A power from all pins of 5V
- DCS (Dual Connector System) to use both sides
- Internal RS232 controller for transfer date between PC and Grape-Express Mini
- Power regulation chip
- No interruption in the program if the USB cable will disconnected
- User LEDs to show the status of the battery and the wifi module
- Second I2C bus on the Bluetooth module (254 devices possible)
- Two different 3,3V safe supply for internal power
- Battery life for about 6h (average usage of 85mAh), short circuit protection
- Battery is fully charged in 20 minutes
- Also work with Arduino
- Short circuit protection and overheating protection of the whole system
Support is very important. We are here for you. Ask us your questions. If you have a problem with any of the components, we are here to help. We can offer support by mail and skype. So your project will always be a success. Just register on the website and ask the question.
Don't forget, designed and produced in Switzerland. The world famous swiss quality is also in our products.
The Grape-Express will be supported on Windows and macOS computers with the USB. Atmel studio is only available on windows. Arduino studio is available on Windows and macOS. The board is compatible with any operating system.
What's the money for?
Right now we have a fully working production model of the Grape-Express Mini. All we need now is to get enough money to get the first batch of boards started! Immediately after the campaign ends we will begin producing your very own Grape-Express Mini.
The future of Grape-Express Mini
In the future, example projects will be available on the website to make developing even easier. Modules for example, sensors, motor drivers or even RGB drivers will come to the website. An adapter is being developed to make Arduino boards compatible with the Grape-Express Mini. If Grape-Express Mini is a success, a smaller version and a larger version will be developed that are even more powerful. All these things will appear on the website.
Risks and challenges
The grape-Express Mini has been developed in the last year. The board is in the final stage. I tested every single part of the boards to ensure the functioning. A big difficulty will be the production but I could already talk to someone who helps me with this. It is also hard to have a cheap price for the board, some components are very expensive, but I am in contact with some companies to offer the best possible price. But these posts no longer constitute a challenge. On the whole, I will be able to handle the problems well.Learn about accountability on Kickstarter
- (40 days)